Use class name indexes instead of class names when evaluating aggregates. Class name lookup followed by string comparison takes significantly longer time then comparison of the class name indexes. For node type comparison it is also much faster to compare its integer value instead of strings.
Created attachment 131835 [details] Patch
Comment on attachment 131835 [details] Patch Please ignore this patch.
Created attachment 131863 [details] Patch
This patch makes _buildAggregates ~ 35% faster.
Comment on attachment 131863 [details] Patch lgtm
Committed r110707: <http://trac.webkit.org/changeset/110707>